The invention is related to a one-way clutch, comprising at least two concentric ring means, one of said ring means carrying at least one ratchet pawl, and the other of said ring means comprising ratchet teeth which engage said at least one ratchet pawl so as to allow relative rotational movement of said at least two ring means in one rotational direction, and to provide a clutch between those ring means in the opposite rotational direction.
Such one-way clutches are generally known, and are e.g. applied in the automotive field, in particular in automatic transmissions.
The object of the invention is to provide a one-way clutch having a construction which is improved with respect to stiffness, ease of manufacture and durability. This object is achieved in that at least one of said ring means comprises two identical ring halves which are connected to each other and which at least partly enclose the other ring means at axially opposite ends.
The ring means which comprises two identical ring halves, is relatively easy and cheap with respect to manufacturing. Moreover, it is possible to provide a sturdy, self-contained unit due to the fact that the other ring means can be enclosed, and therefore be held captive, between the two rings.
Preferably, the identical ring halves constitute an inner ring means, each ring half being provided with a radially outwardly extending flange and axially extending sleeve means, said sleeve means fitting together so as to provide a full sleeve.
The axially extending sleeve means of both ring halves are intermitted in such a way, that a full sleeve is obtained. Preferably, the sleeve means of each ring half comprises at least one axially extending sleeve part which stretches over less than the full circumference of said ring half, said sleeve parts of said ring halves being complementary.
According to the most preferred embodiment, each sleeve means of each ring half comprises two sleeve parts, which are regularly spaced in circumferential direction.
The ratchet mechanism which provides a fixed coupling between the ring means in one rotational direction, and which allows relative rotations in the other direction, can be carried out in several ways. According to a first possibility, at least one sleeve part is provided with a radially outwardly extending slot, which accommodates a spring-biassed ratchet pawl.
In this embodiment, the ratchet pawl is freely translatably in radial direction, a blade spring being provided at its radially inner end for constantly urging the ratchet pawl in radially outward direction.
According to an alternative embodiment, a ratchet pawl may be provided which is pivotable.
The outer ring means may comprise an axially extending outer sleeve which surrounds the flanges of both rings of the inner ring means, and radially inwardly protruding ratchet teeth accommodated between said flanges.
According to a further embodiment, one of the ring means may comprise at least one ratchet pawl which is movable in axial direction, and the other ring means may comprise ratchet teeth on a radially extending surface of said other ring means.
The ring halves of the inner ring means may be provided with mutually aligned, axially extending slots accommodating a spring clip for mutually connecting said rings.